Clinical presentation and outcome of Guillain-Barré and related syndromes in relation to anti-ganglioside antibodies

Expanding Clinical Spectrum of Anti-GQ1b Antibody Syndrome: A Review

Importance

The discovery of the anti-GQ1b antibody has expanded the nosology of classic Miller Fisher syndrome to include Bickerstaff brainstem encephalitis, Guillain-Barré syndrome with ophthalmoplegia, and acute ophthalmoplegia without ataxia, which have been brought under the umbrella term anti-GQ1b antibody syndrome. It seems timely to define the phenotypes of anti-GQ1b antibody syndrome for the proper diagnosis of this syndrome with diverse clinical presentations. This review summarizes these syndromes and introduces recently identified subtypes.

Observations

Although ophthalmoplegia is a hallmark of anti-GQ1b antibody syndrome, recent studies have identified this antibody in patients with acute vestibular syndrome, optic neuropathy with disc swelling, and acute sensory ataxic neuropathy of atypical presentation. Ophthalmoplegia associated with anti-GQ1b antibody positivity is complete in more than half of the patients but may be monocular or comitant. The prognosis is mostly favorable; however, approximately 14% of patients experience relapse.

Conclusions and Relevance

Anti-GQ1b antibody syndrome may present diverse neurological manifestations, including ophthalmoplegia, ataxia, areflexia, central or peripheral vestibulopathy, and optic neuropathy. Understanding the wide clinical spectrum may aid in the differentiation and management of immune-mediated neuropathies with multiple presentations.

Tumor necrosis factor α receptor 1A transduces the inhibitory effect on axon regeneration triggered by IgG anti-ganglioside GD1a antibodies

Anti-ganglioside antibodies (anti-Gg Abs) have been linked to delayed/poor clinical recovery in both axonal and demyelinating forms of Guillain-Barrè Syndrome (GBS). In many instances, the incomplete recovery is attributed to the peripheral nervous system's failure to regenerate. The cross-linking of cell surface gangliosides by anti-Gg Abs triggers inhibition of nerve repair in both in vitro and in vivo axon regeneration paradigms. This mechanism involves the activation of the small GTPase RhoA, which negatively modulates the growth cone cytoskeleton. At present, the identity/es of the receptor/s responsible for transducing the signal that ultimately leads to RhoA activation remains poorly understood. The aim of this work was to identify the transducer molecule responsible for the inhibitory effect of anti-Gg Abs on nerve repair. Putative candidate molecules were identified through proteomic mass spectrometry of ganglioside affinity-captured proteins from rat cerebellar granule neurons (Prendergast et al., 2014). These candidates were evaluated using an in vitro model of neurite outgrowth with primary cultured dorsal root ganglion neurons (DRGn) and an in vivo model of axon regeneration. Using an shRNA-strategy to silence putative candidates on DRGn, we identified tumor necrosis factor receptor 1A protein (TNFR1A) as a transducer molecule for the inhibitory effect on neurite outgrowth from rat/mouse DRGn cultures of a well characterized mAb targeting the related gangliosides GD1a and GT1b. Interestingly, lack of TNFr1A expression on DRGn abolished the inhibitory effect on neurite outgrowth caused by anti-GD1a but not anti-GT1b specific mAbs, suggesting specificity of GD1a/transducer signaling. Similar results were obtained using primary DRGn cultures from TNFR1a-null mice, which did not activate RhoA after exposure to anti-GD1a mAbs. Generation of single point mutants at the stalk region of TNFR1A identified a critical amino acid for transducing GD1a signaling, suggesting a direct interaction. Finally, passive immunization with an anti-GD1a/GT1b mAb in an in vivo model of axon regeneration exhibited reduced inhibitory activity in TNFR1a-null mice compared to wild type mice. In conclusion, these findings identify TNFR1A as a novel transducer receptor for the inhibitory effect exerted by anti-GD1a Abs on nerve repair, representing a significant step forward toward understanding the factors contributing to poor clinical recovery in GBS associated with anti-Gg Abs.

Guillain-Barré Syndrome in the COVID-19 Pandemic

There have been several reported cases of severe acute respiratory syndrome (SARS-CoV-2) infection that were associated with an increased incidence of neurological manifestations, including Guillain–Barré syndrome (GBS). This review aims to present information on the reports of GBS associated with coronavirus disease 2019 (COVID-19) infection. Our review is retrospective work examining articles published from the 1 April 2020 to the 8 May 2021 in the English language. We used the diagnostic criteria and classification published by the National Institute of Neurological Disorders and Stroke and Brighton Collaboration. GBS is usually a postinfectious syndrome, but GBS in the COVID-19 pandemic also takes on a para-infectious profile. In the reports, the genetic factor has a role in developing GBS in some patients. In conclusion, the association between COVID-19 and GBS is not very clear. Still, one mechanism is strongly associated with COVID-19 and immune-mediated neurological complications, which is molecular mimicry between SARS-CoV-2 and human autoantigens.

Immune mechanisms, the role of complement, and related therapies in autoimmune neuropathies

INTRODUCTION

Autoimmune neuropathies have diverse presentations and underlying immune mechanisms. Demonstration of efficacy of therapeutic agents that inhibit the complement cascade would confirm the role of complement activation.

AREAS COVERED

A review of the pathophysiology of the autoimmune neuropathies, to identify those that are likely to be complement mediated.

EXPERT OPINION

Complement mediated mechanisms are implicated in the acute and chronic neuropathies associated with IgG or IgM antibodies that target the Myelin Associated Glycoprotein (MAG) or gangliosides in the peripheral nerves. Antibody and complement mechanisms are also suspected in the Guillain-Barré syndrome and chronic inflammatory demyelinating neuropathy, given the therapeutic response to plasmapheresis or intravenous immunoglobulins, even in the absence of an identifiable target antigen. Complement is unlikely to play a role in paraneoplastic sensory neuropathy associated with antibodies to HU/ANNA-1 given its intracellular localization. In chronic demyelinating neuropathy with anti-nodal/paranodal CNTN1, NFS-155, and CASPR1 antibodies, myotonia with anti-VGKC LGI1 or CASPR2 antibodies, or autoimmune autonomic neuropathy with anti-gAChR antibodies, the response to complement inhibitory agents would depend on the extent to which the antibodies exert their effects through complement dependent or independent mechanisms. Complement is also likely to play a role in Sjogren's, vasculitic, and cryoglobulinemic neuropathies.

A Case of Pharyngeal-Cervical-Brachial Variant of Guillain-Barré Syndrome With Bilateral Glossopharyngeal Paralysis

Guillain-Barré Syndrome (GBS) is a rapidly evolving autoimmune inflammatory disease of the peripheral nerves. It classically presents with progressive symmetrical ascending muscle weakness and hyporeflexia. The pharyngeal-cervical-brachial (PCB) variant is a rare variant of GBS that is characterized by axonal rather than demyelinating neuropathy and presents with rapidly progressive oropharyngeal (facial palsy, dysarthria) and cervicobrachial weakness, associated upper limb weakness, and hyporeflexia. Because it is rare, the PCB variant of GBS is unfamiliar to many neurologists and it is often misdiagnosed as stroke, myasthenia gravis, or botulism. The prevalence of this variant is estimated to be about 3% of all GBS patients. We describe the only known case presentation of the PCB variant of GBS that presents with bilateral glossopharyngeal paralysis. A 39-year-old African American female presented with progressive oropharyngeal and cervicobrachial weakness along with bilateral glossopharyngeal paralysis. The patient was diagnosed based on clinical suspicion, presentation, and serum ganglioside antibodies.

Determining the Utility of the Guillain-Barré Syndrome Classification Criteria

Background and Purpose

Several variants of Guillain-Barré syndrome (GBS) and Miller Fisher syndrome (MFS) exist, but their frequencies vary in different populations and do not always meet the inclusion criteria of the existing diagnostic criteria. However, the GBS classification criteria by Wakerley and colleagues recognize and define the clinical characteristics of each variant. We applied these criteria to a GBS and MFS cohort with the aim of determining their utility.

Methods

Consecutive GBS and MFS patients presenting to our center between 2010 and 2020 were analyzed. The clinical characteristics, electrophysiological data, and antiganglioside antibody profiles of the patients were utilized in determining the clinical classification.

Results

This study classified 132 patients with GBS and its related disorders according to the new classification criteria as follows: 64 (48.5%) as classic GBS, 2 (1.5%) as pharyngeal-cervical-brachial (PCB) variant, 7 (5.3%) as paraparetic GBS, 29 (22%) as classic MFS, 3 (2.3%) as acute ophthalmoparesis, 2 (1.5%) as acute ataxic neuropathy, 2 (1.5%) as Bickerstaff brainstem encephalitis (BBE), 17 (12.9%) as GBS/MFS overlap, 4 (3%) as GBS/BBE overlap, 1 (0.8%) as MFS/PCB overlap, and 1 (0.8%) as polyneuritis cranialis. The electrodiagnosis was demyelinating in 55% of classic GBS patients but unclassified in 79% of classic MFS patients. Anti-GM1, anti-GD1a, anti-GalNAc-GD1a, and anti-GD1b IgG ganglioside antibodies were more commonly detected in the axonal GBS subtype, whereas the anti-GQ1b and anti-GT1a IgG ganglioside antibodies were more common in classic MFS and its subtypes.

Conclusions

Most of the patients in the present cohort met the criteria of either classic GBS or MFS, but variants were seen in one-third of patients. These findings support the need to recognize variants of both syndromes in order to achieve a more-complete case ascertainment in GBS.

Most of anti-glycolipid IgG-antibodies associated to neurological disorders occur without their IgM counterpart

Background

Different neurological disorders frequently display antibodies against several self-glycans. Increasing evidence supports their pathogenic role; however, far less is known about their origin. Meanwhile, antibodies recognizing non-self glycans appear in normal human serum during immune response to bacteria.

Methods

Using high performance thin layer chromatography-immunostaining, we comparatively evaluated humoral immune response (IgG and IgM immunoreactivity) against glycolipids carrying self-glycans (GM3/GM2/GM1/GD1a/GD1b/GD3/GT1b/GQ1b) and non-self glycans (Forssman/GA1/“A” blood group/Nt7) in sera from 383 patients with neurological disorders along with 87 healthy controls.

Results

In contrast to no healthy controls having anti-self glycan IgG antibodies, one-fifth of patients’ sera had anti-self glycan IgG antibodies: remarkably, 60% of these occurred without IgM antibodies of the same specificity. Contrary to this unusual fact (anti-self glycan IgG occurrence without simultaneous presence of IgM having the same specificity ~ IgG/IgM discordance), all IgG antibodies against non-self glycans occurred simultaneously with their IgM antibody counterpart (i.e. 0% discordance). When analyzed closer, the IgG/IgM discordance frequency for anti-self glycans exhibited a dual trend: below 40% for IgG antibodies against GM2, GM1 and GD1b, and greater than 53% for IgG antibodies against the remaining self glycans. Interestingly, this discordance behavior was common to several different neurological disorders.

Conclusions

Classic immunology principles indicate this anti-self glycan IgG/IgM discordance should not occur in an antibody response; its unusual presence is discussed within the “binding site drift hypothesis” context, where anti-self glycan IgG antibodies could originate from pre-existing IgG recognizing structurally-related non-self glycans.

Electronic supplementary material

The online version of this article (10.1186/s12929-019-0562-5) contains supplementary material, which is available to authorized users.

Increased incidence of axonal Guillain-Barré syndrome in La Spezia area of Italy: A 13-year follow-up study

Guillain-Barré syndrome (GBS) is an acute immune-mediated polyradiculoneuropathy with a worldwide incidence of 0.81-1.89 per 100 000 person-years. In Europe and North America only 5% of patients with GBS have axonal subtypes, which in South America and Asia account for 30%-47% of cases. The aim of our study is to assess the annual incidence and clinical features of GBS in La Spezia area in Italy. A retrospective (from 1 January 2003 to 31 December 2011) followed by a prospective (from 1 January 2012 to 31 December 2015) analysis was carried out on patients admitted to La Spezia hospital who fulfilled the GBS diagnostic criteria. A total of 86 patients (58 men), mean age of 62.7 years (range 21-90), were included. The mean annual incidence rate was 3/100 000 (range: 0.9/100 000-5.37/100 000) significantly higher than the European incidence (P < 0.001). Forty-seven percent were classified as acute inflammatory demyelinating polyradiculoneuropathy (AIDP), 35% as acute motor and motor-sensory axonal neuropathy (AMAN-AMSAN), 13% as variant forms, and 5% were not defined. AIDP was most common in "Golfo dei Poeti" (50%) and "Val di Magra" (63.2%), whereas AMAN/AMSAN prevailed in "Val di Vara" (63.6%) and "Riviera Spezzina" (62.5%) (P = 0.024). In La Spezia area GBS incidence (especially the AMAN subtype) is significantly higher than the incidence reported in Europe. AIDP predominates in the eastern area whereas AMAN/AMSAN in the western, with a significantly different incidence rate (P = 0.003). Prospective studies to assess possible predisposing environmental factors are needed.

Atypical Electrophysiological Findings in a Patient with Acute Motor and Sensory Axonal Neuropathy

Guillain–Barré syndrome (GBS) is an immune-mediated polyradiculoneuropathy with acute onset and rapid clinical worsening; early diagnosis and immunomodulating therapy can ameliorate the course of disease. During the first days, however, nerve conduction studies (NCSs) are not always conclusive. Here, we describe a 73-year-old man presenting with progressive muscular weakness of the lower limbs, ascending to the upper limbs, accompanied by distal sensory disturbances. Neuroimaging of brain and spine and NCSs were unremarkable; cerebrospinal fluid analysis revealed no albuminocytologic dissociation. Based on typical clinical features, and on positivity for serum GD1b-IgM antibodies, GBS with proximal conduction failure at multiple radicular levels was postulated, and a standard regime of intravenous immunoglobulin was administered. Four weeks later, the patient presented with flaccid tetraparesis, areflexia, and reduction of position sense, tingling paresthesias, and initial respiratory distress. Repeat NCS still revealed almost normal findings, except for the disappearance of right ulnar nerve F-waves. A few days thereafter, the patient developed severe respiratory insufficiency requiring mechanical ventilation for 2 weeks. On day 50, NCS revealed for the first time markedly reduced compound muscle action potentials and sensory nerve action potentials in all tested nerves, without signs of demyelination; needle electromyography documented widespread denervation. The diagnosis of acute motor and sensory axonal neuropathy was made. After 3 months of intensive rehabilitation, the patient regained the ability to walk with little assistance and was discharged home. In conclusion, normal NCS findings up to several weeks do not exclude the diagnosis of GBS. Very proximal axonal conduction failure with late distal axonal degeneration should be taken into consideration, and electrodiagnostic follow-up examinations, even employing unusual techniques, are recommended over several weeks after disease onset.

Guillain-Barré Syndrome, variants & forms fruste: Reclassification with new criteria

OBJECTIVES

This study aimed to evaluate the clinical and electrophysiological characteristics of various distinctive classical and localised Guillain-Barré syndrome (GBS) subtypes.

PATIENTS AND METHODS

Clinical characteristics and electrophysiological data of sixty-one consecutive patients admitted between 2012 and 2015 were systematically analysed and reclassified according to the new GBS clinical classification. Neurophysiology was evaluated with Hadden et al.'s vs recently proposed Rajabally et al.'s criteria. Functional severity and clinical outcome of various GBS subtypes were ascertained.

RESULTS

All patients initially identified as GBS or related disorders can be sub-classified into having classical GBS (41, 67%), classic Miller-Fisher Syndrome (MFS) (6, 10%), Pharyngeal-cervical-brachial (PCB) (3, 5%), paraparetic GBS (4, 7%), bifacial weakness with paresthesia (3, 5%), acute ophthalmoparesis (AO) (1, 2%) and overlap syndrome (3, 5%): one (2%) with GBS/Bickerstaff brainstem encephalitis overlap and 2 (3%) with GBS/MFS overlap. Greater proportion of axonal classical GBS (67% vs 55%, p=0.372) seen with Rajabally et al.'s criteria and a predominantly axonal form of paraparetic variant (75%) independent of electrodiagnostic criteria were more representative of Asian GBS cohort. Classical GBS patients had lowest admission and discharge Medical Research Council Sum Score (MRCSS), greater functional disability and longest length of in-patient stay. Twenty (20/21, 95%) patients who needed mechanical ventilation had classical GBS. Patients required repeated dose of intravenous immunoglobulin (5/6, 3%) or plasma exchange (4/4, 100%) more frequently had axonal form of classical GBS.

CONCLUSION

Phenotype recognition based on new GBS clinical classification, supported by electrodiagnostic study permits more precise clinical subtypes determination and outcome prognostication.

Clinical classification of 103 Japanese patients with Guillain-Barré syndrome

Guillain-Barré syndrome (GBS) is the commonest cause of flaccid paralysis worldwide. Miller Fisher syndrome (MFS) is a variant of GBS characterized by ophthalmoplegia and ataxia. Together GBS and MFS form a continuum of discrete and overlapping subtypes, the frequency of which remains unknown. We retrospectively analysed the clinical features (antecedent symptoms, pattern of neurological weakness or ataxia, presence of hypersomnolence) of 103 patients at a single hospital in Japan. Patients were then classified according to new diagnostic criteria (Wakerley et al., 2014). Laboratory data (neurophysiology and anti-ganglioside antibody profiles) were also analysed. According to the new diagnostic criteria, the 103 patients could be classified as follows: classic GBS 73 (71%), pharyngeal-cervical-brachial weakness 2 (2%), acute pharyngeal weakness 0 (0%), paraparetic GBS 1 (1%), bifacial weakness with paraesthesias 1 (1%), polyneuritis cranialis 0 (0%), classic MFS 18 (17%), acute ophthalmoparesis 1 (1%), acute ptosis 0 (0%), acute mydriasis 0 (0%), acute ataxic neuropathy 1 (1%), Bickerstaff brainstem encephalitis 3 (3%), acute ataxic hypersomnolence 0 (0%), GBS and MFS overlap 1 (1%), GBS and Bickerstaff brainstem encephalitis overlap 1 (1%), MFS and pharyngeal-cervical-brachial weakness overlap 1 (1%). Application of the new clinical diagnostic criteria allowed accurate retrospective diagnosis and classification of GBS and MFS subtypes.

Anti-glycan antibodies halt axon regeneration in a model of Guillain Barrè Syndrome axonal neuropathy by inducing microtubule disorganization via RhoA-ROCK-dependent inactivation of CRMP-2

Several reports have linked the presence of high titers of anti-Gg Abs with delayed recovery/poor prognosis in GBS. In most cases, failure to recover is associated with halted/deficient axon regeneration. Previous work identified that monoclonal and patient-derived anti-Gg Abs can act as inhibitory factors in an animal model of axon regeneration. Further studies using primary dorsal root ganglion neuron (DRGn) cultures demonstrated that anti-Gg Abs can inhibit neurite outgrowth by targeting gangliosides via activation of the small GTPase RhoA and its associated kinase (ROCK), a signaling pathway common to other established inhibitors of axon regeneration. We aimed to study the molecular basis of the inhibitory effect of anti-Gg abs on neurite outgrowth by dissecting the molecular dynamics of growth cones (GC) cytoskeleton in relation to the spatial-temporal analysis of RhoA activity. We now report that axon growth inhibition in DRGn induced by a well characterized mAb targeting gangliosides GD1a/GT1b involves: i) an early RhoA/ROCK-independent collapse of lamellipodia; ii) a RhoA/ROCK-dependent shrinking of filopodia; and iii) alteration of GC microtubule organization/and presumably dynamics via RhoA/ROCK-dependent phosphorylation of CRMP-2 at threonine 555. Our results also show that mAb 1B7 inhibits peripheral axon regeneration in an animal model via phosphorylation/inactivation of CRMP-2 at threonine 555. Overall, our data may help to explain the molecular mechanisms underlying impaired nerve repair in GBS. Future work should define RhoA-independent pathway/s and effectors regulating actin cytoskeleton, thus providing an opportunity for the design of a successful therapy to guarantee an efficient target reinnervation.

Relationship Between Cerebrospinal Fluid Protein Levels and Electrophysiologic Abnormalities in Guillain-Barré Syndrome

OBJECTIVES

The cerebrospinal fluid (CSF) protein level is known to be elevated in patients with Guillain-Barré syndrome (GBS). This report correlates the degree of CSF protein elevation with the number of electrophysiologic abnormalities on nerve conduction study (NCS).

METHODS

We reviewed 38 patients admitted to our institution with a diagnosis of GBS and had both a measured CSF protein level and a NCS within 24 hours of each other.

RESULTS

CSF protein level correlates with the number of NCS demyelination criteria, as described by Cornblath, in patients with GBS.

CONCLUSIONS

This retrospective study is the first to demonstrate a relationship between the CSF protein level and the electrophysiologic abnormalities that accompany GBS.

Dissecting the Role of Anti-ganglioside Antibodies in Guillain-Barré Syndrome: an Animal Model Approach

Guillain-Barré syndrome (GBS) is an autoimmune polyneuropathy disease affecting the peripheral nervous system (PNS). Most of the GBS patients experienced neurological symptoms such as paresthesia, weakness, pain, and areflexia. There are also combinations of non-neurological symptoms which include upper respiratory tract infection and diarrhea. One of the major causes of GBS is due largely to the autoantibodies against gangliosides located on the peripheral nerves. Gangliosides are sialic acid-bearing glycosphingolipids consisting of a ceramide lipid anchor with one or more sialic acids attached to a neutral sugar backbone. Molecular mimicry between the outer components of oligosaccharide of gangliosides on nerve membrane and lipo-oligosaccharide of microbes is thought to trigger the autoimmunity. Intra-peritoneal implantation of monoclonal ganglioside antibodies secreting hybridoma into animals induced peripheral neuropathy. Recent studies demonstrated that injection of synthesized anti-ganglioside antibodies raised by hybridoma cells into mice initiates immune response against peripheral nerves, and eventually failure in peripheral nerve regeneration. Accumulating evidences indicate that the conjugation of anti-ganglioside monoclonal antibodies to activating FcγRIII present on the circulating macrophages inhibits axonal regeneration. The activation of RhoA signaling pathways is also involved in neurite outgrowth inhibition. However, the link between these two molecular events remains unresolved and requires further investigation. Development of anti-ganglioside antagonists can serve as targeted therapy for the treatment of GBS and will open a new approach of drug development with maximum efficacy and specificity.

Autoimmune peripheral neuropathies

Peripheral nervous system axons and myelin have unique potential protein, proteolipid, and ganglioside antigenic determinants. Despite the existence of a blood-nerve barrier, both humoral and cellular immunity can be directed against peripheral axons and myelin. Molecular mimicry may be triggered at the systemic level, as was best demonstrated in the case of bacterial oligosaccharides. The classification of immune neuropathy has been expanded to take into account specific syndromes that share unique clinical, electrophysiological, prognostic and serological features. Guillain-Barré syndrome encompasses a classical syndrome of acute demyelinating polyradiculoneuropathy and many variants: axonal motor and sensory, axonal motor, Miller-Fisher, autonomic, and sensory. Similarly, chronic immune neuropathy is composed of classic chronic inflammatory demyelinating polyradiculoneuropathy and variants characterized as multifocal (motor or sensorimotor), sensory, distal symmetric, and syndromes associated with monoclonal gammopathy. Among putative biomarkers, myelin associated glycoprotein and several anti-ganglioside autoantibodies have shown statistically significant associations with specific neuropathic syndromes. Currently, the strongest biomarker associations are those linking Miller-Fisher syndrome with anti-GQ1b, multifocal motor neuropathy with anti-GM1, and distal acquired symmetric neuropathy with anti-MAG antibodies. Many other autoantibody associations have been proposed, but presently lack sufficient specificity and sensitivity to qualify as biomarkers. This field of research has contributed to the antigenic characterization of motor and sensory functional systems, as well as helping to define immune neuropathic syndromes with widely different clinical presentation, prognosis and response to therapy. Serologic biomarkers are likely to become even more relevant with the advent of new targeted forms of immunotherapy, such as monoclonal antibodies.

Chronic Bickerstaff's encephalitis with cognitive impairment, a reality?

Background

Bickerstaff’s encephalitis (BE) is an acute post-infectious demyelinating disease with albuminocytological dissociation. A chronic form has rarely been described previously.

Case presentation

A 44-year-old man was hospitalized for drowsiness, cognitive complaint limb weakness, ataxia and sensory disturbance after diarrhea. Neuropsychological evaluation showed slowing, memory and executive function impairment, while analysis of the CSF showed albuminocytological dissociation. Immunologic tests showed positive anti-ganglioside antibodies (anti-GM1 IgM, anti-GD1a IgG and anti-GD1b IgM). Brain MRI was normal but SPECT showed bilateral temporal and frontal hypoperfusion. Outcome under immunoglobulin treatment (IVIG) was favorable with an initial improvement but was marked by worsening after a few weeks. Consequently, the patient was treated with IVIG every 2 months due to the recurrence of symptoms after 6 weeks.

Conclusion

This case raises the question of the existence of a chronic form of BE with cognitive impairment, in the same way as chronic inflammatory demyelinating polyneuropathy is considered to be a chronic form of Guillain–Barré syndrome.

Fcγ receptor-mediated inflammation inhibits axon regeneration

Anti-glycan/ganglioside antibodies are the most common immune effectors found in patients with Guillain-Barré Syndrome, which is a peripheral autoimmune neuropathy. We previously reported that disease-relevant anti-glycan autoantibodies inhibited axon regeneration, which echo the clinical association of these antibodies and poor recovery in Guillain-Barré Syndrome. However, the specific molecular and cellular elements involved in this antibody-mediated inhibition of axon regeneration are not previously defined. This study examined the role of Fcγ receptors and macrophages in the antibody-mediated inhibition of axon regeneration. A well characterized antibody passive transfer sciatic nerve crush and transplant models were used to study the anti-ganglioside antibody-mediated inhibition of axon regeneration in wild type and various mutant and transgenic mice with altered expression of specific Fcγ receptors and macrophage/microglia populations. Outcome measures included behavior, electrophysiology, morphometry, immunocytochemistry, quantitative real-time PCR, and western blotting. We demonstrate that the presence of autoantibodies, directed against neuronal/axonal cell surface gangliosides, in the injured mammalian peripheral nerves switch the proregenerative inflammatory environment to growth inhibitory milieu by engaging specific activating Fcγ receptors on recruited monocyte-derived macrophages to cause severe inhibition of axon regeneration. Our data demonstrate that the antibody orchestrated Fcγ receptor-mediated switch in inflammation is one mechanism underlying inhibition of axon regeneration. These findings have clinical implications for nerve repair and recovery in antibody-mediated immune neuropathies. Our results add to the complexity of axon regeneration in injured peripheral and central nervous systems as adverse effects of B cells and autoantibodies on neural injury and repair are increasingly recognized.

Enhanced, sialoadhesin-dependent uptake of Guillain-Barre syndrome-associated Campylobacter jejuni strains by human macrophages

Molecular mimicry between Campylobacter jejuni sialylated lipooligosaccharides (LOS) and human nerve gangliosides can trigger the production of cross-reactive antibodies which induce Guillain-Barré syndrome (GBS). To better understand the immune events leading to GBS, it is essential to know how sialylated LOS are recognized by the immune system. Here, we show that GBS-associated C. jejuni strains bind to human sialoadhesin (hSn), a conserved, mainly macrophage-restricted I-type lectin. Using hSn-transduced THP-1 cells, we observed that C. jejuni strains with α(2,3)-sialylated LOS, including strains expressing GM1a- and GD1a-like epitopes, bind to hSn. This observation is of importance, as these epitopes are frequently the targets of the cross-reactive antibodies detected in GBS patients. Interestingly, the Sn binding domains were not constitutively exposed on the surface of C. jejuni. Heat inactivation and the environmental conditions which food-borne C. jejuni encounters during its passage through the intestinal tract, such as low pH and contact with bile constituents, exposed LOS and facilitated Sn binding. Sn binding enhanced bacterial uptake and increased the production of interleukin-6 (IL-6) by primary human Sn-expressing monocyte-derived macrophages compared to control conditions, where Sn was blocked using neutralizing antibodies or when nonsialylated C. jejuni was used. Sn-mediated uptake has been reported to enhance humoral immune responses. As C. jejuni strains expressing ganglioside mimics GD1a and GM1a are closely associated with GBS, Sn binding may be a determining event in the production of cross-reactive antibodies and the development of GBS.

Antibody testing in peripheral nerve disorders

The identification of autoantibodies associated with dysimmune neuropathies was a major contribution to the characterization of peripheral nerve disorders, the understanding of their pathophysiology, and the clinical diagnosis of neuropathies. Antibodies directed to GM1, GQ1b, and disyalilated gangliosides, and anti-MAG antibodies are very useful in the diagnosis of acute or chronic motor or sensory-motor neuropathies with or without monoclonal IgM. Anti-onconeural anti-Hu and anti-CV2/CRMP antibodies allow when they are detected the diagnosis of paraneoplastic neuropathies. This chapter focuses on the description of these antibodies as diagnostic markers and on their immunopathogenesis. We give a background overview on the origin of these antibodies, their detection, and review those studies, which clearly show that these antibodies are capable of binding to the target tissues in peripheral nerve and thereby can exert a variety of pathophysiological effects. The corresponding electrophysiological and histological changes observed both in human and animal models are exemplified in order to get a better understanding of the immune mechanisms of these antibody-mediated neuropathies.

Implications of Lymphocyte Anergy to Glycolipids in Multiple Sclerosis (MS): iNKT Cells May Mediate the MS Infectious Trigger

Immunogenic lipids may play key roles in host defenses against infection and in generating autoimmune inflammation and organ-specific damage. In multiple sclerosis (MS) there are unequivocal autoimmune features and vulnerability to aggravation or induction by microbial or viral infection. We have found glycolipid-driven anergy of circulating lymphocytes in MS indicating that this immune response is affected in MS and the robust effects of iNKT activation with potent cellular and cytokine activities emphasizes its potential importance. Diverse glycolipids including the endogenous myelin acetylated-galactosylceramides (AcGalCer) can drive activation that could be critical to the inflammatory demyelination in the central nervous system and clinical consequences. The iNKT cells and their invariant or iTCR (Vα24Jα18Vβ11) receptor an innate defense–a discrete immune arm that is separate from peptide-driven acquired immune responses. This offers new possibilities for insight including a likelihood that the pattern recognition of exogenous microbial and myelin immunogens can overlap and cross-react especially in an inflammatory milieu.

Erythropoietin enhances nerve repair in anti-ganglioside antibody-mediated models of immune neuropathy

Guillain-Barré syndrome (GBS) is a monophasic immune neuropathic disorder in which a significant proportion of patients have incomplete recovery. The patients with incomplete recovery almost always have some degree of failure of axon regeneration and target reinnervation. Anti-ganglioside antibodies (Abs) are the most commonly recognized autoimmune markers in all forms of GBS and specific Abs are associated with the slow/poor recovery. We recently demonstrated that specific anti-ganglioside Abs inhibit axonal regeneration and nerve repair in preclinical models by activation of small GTPase RhoA and its downstream effectors. The objective of this study was to determine whether erythropoietin (EPO), a pleiotropic cytokine with neuroprotective and neurotrophic properties, enhances nerve regeneration in preclinical cell culture and animal models of autoimmune neuropathy/nerve repair generated with monoclonal and patient derived Abs. Primary neuronal cultures and a standardized sciatic crush nerve model were used to assess the efficacy of EPO in reversing inhibitory effects of anti-ganglioside Abs on nerve repair. We found that EPO completely reversed the inhibitory effects of anti-ganglioside Abs on axon regeneration in cell culture models and significantly improved nerve regeneration/repair in an animal model. Moreover, EPO-induced proregenerative effects in nerve cells are through EPO receptors and Janus kinase 2/Signal transducer and activator of transcription 5 pathway and not via early direct modulation of small GTPase RhoA. These preclinical studies indicate that EPO is a viable candidate drug to develop further for neuroprotection and enhancing nerve repair in patients with GBS.

Preceding infections and anti-ganglioside antibody profiles assessed by a dot immunoassay in 306 French Guillain-Barré syndrome patients

We describe by an in-house dot immunoassay, specific anti-ganglioside and sulfatide antibodies, by comparing the results from a large group of 134 infected French GBS patients and those from 172 noninfected French GBS and 142 control groups. A recent infection was identified in 134/306 (43.8%) GBS patients: Campylobacter jejuni (24.6%) was the most common agent, followed by cytomegalovirus (12.4%), Mycoplasma pneumoniae (3.2%) and Epstein-Barr virus (1.3%). Anti-ganglioside antibodies were detected in 97/306 (31.7%) of total GBS patients, 82/134 (61.2%) of GBS patients with a recent identified infection and 15/172 (8.7%) of the patients without identified infection. According to the specificities and antibody classes, four specific IgG antibody profiles were individualised against the two major GM1 and GD1a gangliosides in motor axonal C. jejuni-associated GBS variants, against GQ1b and disialylated gangliosides in Miller Fisher syndrome and its variants. One specific IgM profile against GM2 was found in 16/38 (42%) of severe sensory demyelinating CMV-associated GBS and in 8/17 (47%) of subjects with recent CMV infection with no neurological disease. IgG or IgM antibodies to GM1 were found in 5/10 M. pneumoniae-infected patients. IgM antibodies to GM1 were observed in the control groups, 15% of the 74 patients with amyotrophic lateral sclerosis, 19% of the 51 patients with chronic inflammatory demyelinating polyneuropathy, and 9% of the 21 healthy control subjects. The fine specificity of the four IgG antibody profiles and the IgM anti-GM2 profile is closely related to the nature of the preceding infections and the pattern of clinical features.

Anti-ganglioside antibody-mediated activation of RhoA induces inhibition of neurite outgrowth

Anti-ganglioside antibodies (Abs) are strongly associated with axonal forms of Guillain Barré syndrome (GBS). Some studies indicate that these Abs, including those with GD1a reactivity, are associated with poor prognosis and/or incomplete recovery. We recently demonstrated that a disease-relevant anti-ganglioside Ab with GD1a reactivity inhibits axon regeneration after PNS injury in an animal model (Lehmann et al., 2007). An implication of these findings is that anti-GD1a Abs can mediate inhibition of axon regeneration and limit recovery in some patients with GBS. The downstream inhibitory intracellular signaling that mediates anti-ganglioside Ab-induced axon inhibition remains unclear. In the current study, we show that disease-relevant and GBS patient's anti-ganglioside Abs can inhibit neurite outgrowth in dissociated primary neuronal cultures. Activation of small GTPase RhoA and its key downstream effector Rho kinase (ROCK) are critical mediators of growth cone and neurite outgrowth inhibition. Therefore, we examined the role of these intracellular signaling molecules in our primary neuronal cultures by molecular and pharmacologic approaches. Our results show that the Ab-mediated inhibition of neurite outgrowth involves the activation of RhoA and ROCK pathway and this activation is through the engagement of specific cell-surface gangliosides by Abs. In summary, these studies directly link patient autoantibodies to an intracellular inhibitory signaling pathway involved in anti-ganglioside Ab-mediated inhibition of neurite outgrowth.

Anti-glycolipid GM2-positive Guillain-Barre syndrome due to hepatitis E infection

BACKGROUND

Hepatitis E infection is most prevalent in developing countries with poor sanitation, but can also occur apparently sporadically in more developed areas.

CASE

We here report a second European case of Guillain-Barre syndrome due to hepatitis E infection in association with anti-glycolipid GM2 antibody.

INTERPRETATION

This is likely to be a specific association involving molecular mimicry, and further European cases can therefore be expected.

Passive transfer of IgG anti-GM1 antibodies impairs peripheral nerve repair

Anti-GM1 antibodies are present in some patients with autoimmune neurological disorders. These antibodies are most frequently associated with acute immune neuropathy called Guillain-Barré syndrome (GBS). Some clinical studies associate the presence of these antibodies with poor recovery in GBS. The patients with incomplete recovery have failure of nerve repair, particularly axon regeneration. Our previous work indicates that monoclonal antibodies can inhibit axon regeneration by engaging cell surface gangliosides (Lehmann et al., 2007). We asked whether passive transfer of human anti-GM1 antibodies from patients with GBS modulate axon regeneration in an animal model. Human anti-GM1 antibodies were compared with other GM1 ligands, cholera toxin B subunit and a monoclonal anti-GM1 antibody. Our results show that patient derived anti-GM1 antibodies and cholera toxin beta subunit impair axon regeneration/repair after PNS injury in mice. Comparative studies indicated that the antibody/ligand-mediated inhibition of axon regeneration is dependent on antibody/ligand characteristics such as affinity-avidity and fine specificity. These data indicate that circulating immune effectors such as human autoantibodies, which are exogenous to the nervous system, can modulate axon regeneration/nerve repair in autoimmune neurological disorders such as GBS.

Lipopolysaccharide-induced inflammatory cytokine production by Schwann's cells dependent upon TLR4 expression

Signaling of Toll-like receptor-4 (TLR4) through its cognate ligand endotoxin appears critical in tissue inflammation associated with bacterial infection. We found that anti-GM1 antibody (Ab) enhances TLR4 expression in Schwann's cells (SCs) in vivo and in vitro. The anti-GM1 Ab-treated SC also showed increased release of pro-inflammation cytokines IL-1beta and TNF-alpha after incubation with lipopolysaccharide (LPS). Furthermore, down-regulation of TLR4 expression using antisense oligonucleotides targeted to TLR4 mRNA suppressed cytokine production in LPS stimulated cultures. These findings suggest that elevation of TLR4 expression increases sensitivity of SC to LPS and production of inflammatory mediators that may be responsible for peripheral nerve dysfunction.

Clinical and immunological spectrum of the Miller Fisher syndrome

The Miller Fisher syndrome (MFS), characterized by ataxia, areflexia, and ophthalmoplegia, was first recognized as a distinct clinical entity in 1956. MFS is mostly an acute, self-limiting condition, but there is anecdotal evidence of benefit with immunotherapy. Pathological data remain scarce. MFS can be associated with infectious, autoimmune, and neoplastic disorders. Radiological findings have suggested both central and peripheral involvement. The anti-GQ1b IgG antibody titer is most commonly elevated in MFS, but may also be increased in Guillain-Barré syndrome (GBS) and Bickerstaff's brainstem encephalitis (BBE). Molecular mimicry, particularly in relation to antecedent Campylobacter jejuni and Hemophilus influenzae infections, is likely the predominant pathogenic mechanism, but the roles of other biological factors remain to be established. Recent studies have demonstrated the presence of neuromuscular transmission defects in association with anti-GQ1b IgG antibody, both in vitro and in vivo. Collective findings from clinical, radiological, immunological, and electrophysiological techniques have helped to define MFS, GBS, and BBE as major disorders within the proposed spectrum of anti-GQ1b IgG antibody syndrome.

Antibody testing in peripheral neuropathies

Many autoantibodies have been described in association with peripheral neuropathy, but the use of antibody testing in clinical practice remains a matter of some debate. Serum autoantibodies to gangliosides or glycoproteins are implicated in a variety of sensory and motor neuropathy syndromes. Paraneoplastic antibodies help identify patients who have a neuropathy related to an underlying malignancy. Detection of an autoantibody in the right clinical setting provides some evidence that the peripheral nerve disturbance is immune mediated and that immunomodulatory therapy may be of benefit.

Passive immunization with anti-ganglioside antibodies directly inhibits axon regeneration in an animal model

Recent studies have proposed that neurite outgrowth is influenced by specific nerve cell surface gangliosides, which are sialic acid-containing glycosphingolipids highly enriched in the mammalian nervous system. For example, the endogenous lectin, myelin-associated glycoprotein (MAG), is reported to bind to axonal gangliosides (GD1a and GT1b) to inhibit neurite outgrowth. Clustering of gangliosides in the absence of inhibitors such as MAG is also shown to inhibit neurite outgrowth in culture. In some human autoimmune PNS and CNS disorders, autoantibodies against GD1a or other gangliosides are implicated in pathophysiology. Because of neurobiological and clinical relevance, we asked whether anti-GD1a antibodies inhibit regeneration of injured axons in vivo. Passive transfer of anti-GD1a antibody severely inhibited axon regeneration after PNS injury in mice. In mutant mice with altered ganglioside or complement expression, inhibition by antibodies was mediated directly through GD1a and was independent of complement-induced cytolytic injury. The impaired regenerative responses and ultrastructure of injured peripheral axons mimicked the abortive regeneration typically seen after CNS injury. These data demonstrate that inhibition of axon regeneration is induced directly by engaging cell surface gangliosides in vivo and imply that circulating autoimmune antibodies can inhibit axon regeneration through neuronal gangliosides independent of endogenous regeneration inhibitors such as MAG.

Anti-phospholipid antibodies in serum from patients with Guillain-Barré syndrome

OBJECTIVE

The Guillain-Barré syndrome (GBS) is an acute inflammatory polyneuropathy related to autoimmunity. However, no conclusive etiological concept has yet been found. We examined the variation in autoantibodies to lipids in serum of GBS patients in response to the course of the disease but investigated titer modifications during treatment with gamma-globulin.

DESIGN AND SETTING

Prospective clinical study in a 14-bed general ICU.

PATIENTS

Nine patients with GBS and nine controls were included in the study.

MEASUREMENTS AND RESULTS

Four blood samples were obtained before and after treatment. Serum samples, diluted 1:60, were tested by enzyme-linked immunosorbent assay for IgM, IgA, and IgG antibodies to phosphatidylcholine, phosphatidylinositol, cardiolipin, phosphatidic acid, phosphatidylserine, phosphatidylglycerol, phosphatidylethanolamine, sphingomyelin, and gangliosides. Anti-phospholipid antibodies of the IgM, IgA, and IgG families were detected in all GBS patients but in none of the controls. Phosphatidylinositol, cardiolipin, phosphatidylcholine, and phosphatidic acid were the main antigens. All patients developed anti-phosphatidylinositol antibodies of the IgM family and anti-cardiolipin antibodies of the IgA and IgG families. A decrease in the level of anti-phospholipid autoantibodies was observed after 1 day of treatment with gamma-globulin. Two days after ending gamma-globulin administration the IgG antibodies increased again.

CONCLUSIONS

Our findings suggest that in GBS there is an extensive immune reaction, which is altered after gamma-globulin treatment. Anti-cardiolipin and anti-phosphatidylinositol antibodies could be useful markers for the response to treatment.

Miller-Fisher syndrome mimicking intracranial hypertension following head trauma

INTRODUCTION

Miller-Fisher syndrome (MFS) is a polyneuropathy with benign outcome characterized by ophthalmoplegia, limb ataxia and tendon areflexia. Impaired consciousness level and intracranial hypertension are very rare symptoms in MFS.

CASE REPORT

We describe the case of a 5-year-old girl who showed intracranial hypertension, transient coma and respiratory failure after mild head injury; moreover the patient showed mild ataxia, areflexia, ophthalmoplegia and autonomic disturbances. These symptoms were suggestive of MFS. Electrophysiologic studies and laboratory tests confirmed the diagnosis and immunoglobulins and steroids were given. The child showed a progressive clinical improvement and the final outcome was good.

CONCLUSION

This case, initially managed as trauma injury due to the presence of suggestive signs and clinical history, maskered an atypical presentation of Miller-Fisher syndrome, a rare disorder of central nervous system.

Treatment of dysimmune neuropathies

Several therapies are currently used in dys-immune neuropathies including steroids,plasma exchange (PE), high-dose intravenous immunoglobulins(IVIg), and immuno-suppressive agents (IS). Even if there is substantial evidence that these treatments may improve the course of the neuropathy, their effectiveness is far from being complete and is sometime hampered by the occurrence of associated side effects. In Guillain-Barré syndrome (GBS),IVIg and PE are similarly effective in accelerating the recovery but there is still little evidence that they can reduce mortality or long-term disability. Recent reports on the association of intravenous methylprednisolone or interferon-beta (IFN-beta) to IVIg did not result in significant further improvement. In chronic inflammatory demyelinating polyradiculoneuropathy(CIDP) steroids, PE, and IVIG are initially similarly effective. The short-term effect of PE and IVIgand the side effects associated with the long-term use of steroids have prompted the use of several IS, interferon and,more recently, the anti-CD20 monoclonal-antibody Rituximab, but their efficacy has still to be proved in controlled studies. The recent identification of multifocal motor neuropathy(MMN) was shortly followed by the finding of an effective therapy. Almost 80% of patients respond toIVIg whose effect needs to be maintained with periodic infusions for long periods of time, and tends to decrease after several years. Also in this condition a number of immune modulating agents have been used to reduce the frequency or improve the effectiveness of IVIg,but their efficacy has not been sofar confirmed in randomized trials. Similar conclusions can be drawn for neuropathies associated with monoclonal gammopathies where only PE and IVIg have proved to be effective in controlled studies,while the promising initial results obtained with Rituximab in neuropathy associated IgM monoclonal gammopathy awaits confirmation from controlled trials.

Isolated cranial neuropathy associated with anti-glycolipid antibodies

We describe seven patients with isolated cranial neuropathy in whom serum anti-glycolipid antibodies were detected. Trigeminal sensory neuropathy was found in four patients, who had exhibited symptoms for 2 months to 4 years. The other three patients showed facial nerve palsy with or without ophthalmoparesis. Temporal profile analysis of anti-glycolipid antibodies revealed that titers of anti-glycolipid IgM antibodies against GM2 and LM1 gradually decreased in patients having chronic trigeminal sensory neuropathy. In patients with acute trigeminal sensory neuropathy, elevation of anti-LM1 antibody titers continued over 12 months although anti-GalNAc-GD1a antibody disappeared. On the other hand, titers of anti-glycolipid antibodies rapidly decreased in patients with acute facial nerve palsy with or without ophthalmoparesis. We conclude that anti-glycolipid antibodies may play an important role in the development of isolated cranial neuropathy in some patients.

Vaccination and autoimmune disease: what is the evidence?

As many as one in 20 people in Europe and North America have some form of autoimmune disease. These diseases arise in genetically predisposed individuals but require an environmental trigger. Of the many potential environmental factors, infections are the most likely cause. Microbial antigens can induce cross-reactive immune responses against self-antigens, whereas infections can non-specifically enhance their presentation to the immune system. The immune system uses fail-safe mechanisms to suppress infection-associated tissue damage and thus limits autoimmune responses. The association between infection and autoimmune disease has, however, stimulated a debate as to whether such diseases might also be triggered by vaccines. Indeed there are numerous claims and counter claims relating to such a risk. Here we review the mechanisms involved in the induction of autoimmunity and assess the implications for vaccination in human beings.

Bickerstaff's brainstem encephalitis: clinical features of 62 cases and a subgroup associated with Guillain-Barré syndrome

Bickerstaff reported eight patients who, in addition to acute ophthalmoplegia and ataxia, showed drowsiness, extensor plantar responses or hemisensory loss. This condition has been named Bickerstaff's brainstem encephalitis (BBE). One patient had gross flaccid weakness in the four limbs. Presumably because of the rarity of this disorder, there has been no reported study on a large number of patients with BBE. To clarify its clinical features, we reviewed detailed clinical profiles and laboratory findings for 62 cases of BBE diagnosed by the strict criteria of progressive, relatively symmetrical external ophthalmoplegia and ataxia by 4 weeks, and disturbance of consciousness or hyperreflexia. Ninety-two per cent of the patients involved had had an antecedent illness. Besides ophthalmoplegia and ataxia, disturbance of consciousness was frequent (74%), and facial diplegia (45%), Babinski's sign (40%) and pupillary abnormality and bulbar palsy (34%) were present. Almost all the patients had a monophasic remitting course and generally a good outcome. Serum anti-GQ1b IgG antibody was positive in 66%, and MRI showed brain abnormality in 30% of the patients. Another striking feature was the association with flaccid symmetrical tetraparesis, seen in 60% of the patients. An autopsy study of a BBE patient clearly showed the presence of definite inflammatory changes in the brainstem: there was perivascular lymphocytic infiltration with oedema and glial nodules. Electrodiagnostic study results suggested peripheral motor axonal degeneration. Limb weakness in the BBE cases studied was considered the result of overlap with the axonal subtype of Guillain-Barré syndrome. These findings confirm that BBE constitutes a clinical entity and provide additional clinical and laboratory features of BBE. A considerable number of BBE patients have associated axonal Guillain-Barré syndrome, indicative that the two disorders are closely related and form a continuous spectrum.

Detection of anti-ganglioside antibodies in Guillain-Barré syndrome and its variants by the agglutination assay

Sera from 40 patients with Guillain-Barré syndrome (GBS), including the subtypes acute inflammatory demyelinating polyneuropathy (AIDP), acute motor axonal neuropathy (AMAN), acute motor and sensory axonal neuropathy (AMSAN), and Miller Fisher syndrome (MFS) were examined for the presence of anti-ganglioside antibodies using the ganglioside agglutination assay, and the enzyme-linked immunosorbent assay (ELISA). In the ELISA system, sera were tested for IgM and IgG antibodies to GM1, GM2, GD1a, GD1b, GT1b, and GQ1b gangliosides. Antibodies to gangliosides were detected in 21 (53%) of the GBS patients by agglutination assay and in 17 (43%) of the patients by ELISA. Some of the sera reacted with more than one ganglioside. Antibodies were not found in the control sera that were studied. The agglutination assay may be useful for rapid screening of GBS sera for antibodies to multiple gangliosides.

Miller Fisher syndrome with transient coma: comparison with Bickerstaff brainstem encephalitis

We herein report a 4-year-old boy with Miller Fisher syndrome (MFS) who presented with transient coma in addition to the typical triad of internal and external ophthalmoplegia, cerebellar ataxia and areflexia after an influenza type B infection. The electroencephalogram findings revealed intermittently generalized slow wave bursts. The cerebrospinal fluid revealed high protein and a lack of any cellular response. The serum anti-GQ1b IgG antibody was elevated in the acute phase and disappeared in the convalescent phase. The transient coma with the triad of MFS in this patient indicated an extended brainstem lesion including a reticular formation, which is also the responsible lesion of Bickerstaff brainstem encephalitis (BBE), but the magnetic resonance imaging repeatedly showed no abnormal finding. Our patient suggested the involvement of central nervous system in addition to the peripheral nerve injury in MFS. He also suggested that MFS and BBE may belong to the same group of disorders as syndrome of ophthalmoplegia, ataxia and areflexia (SOAA).

Temporal profile of anti-ganglioside antibodies and their relation to clinical parameters and treatment in Guillain-Barré syndrome

Elevated anti-ganglioside antibody levels mainly of anti-GM1 and anti-GD1a specificities have been reported in THE serum of patients with Guillain-Barré syndrome (GBS). The relevance of anti-ganglioside antibodies other than anti-GM1 and anti-GD1a IgG antibodies and the temporal profile of anti-ganglioside antibodies in GBS is less clear. We studied serum antibodies to GM1, GD1a, GD1b, GQ1b, sulfatide and cardiolipin of the IgM, IgG and IgA classes over the course of GBS in patients who were untreated or treated with high dose intravenous immunoglobulin (IvIg). Antibodies to GD1b, GQ1b, sulfatide and cardiolipin were not detected in the sera of the GBS patients examined in this study. Anti-GM1 IgG titers peaked around 40 days and anti-GD1a IgM around 90 days after GBS onset. Titers of anti-GM1 IgG antibodies decreased following IvIg treatment. Patients with antibody peaks, defined as fivefold or higher increase in antibody titer compared to the lowest antibody titer over the course of GBS, had higher disability scores during the first two weeks of GBS and a worse clinical outcome (anti-GM1 IgG and anti-GD1a IgM antibody peaks) and axonal damage (anti-GD1a IgM antibody peaks), compared to patients without peak antibody titers. Anti-GM1 IgG and anti-GD1a IgM antibodies are thus strongly associated with more severe- and predominantly axonal cases of GBS. The appearance of anti-GM1 IgG and anti-GD1a antibody peaks in the serum after the termination of the acute phase of GBS suggests that these antibodies are produced secondary to nerve damage in GBS. The data does not exclude the possibility that secondarily secreted anti-GM1 IgG and anti-GD1a IgM antibodies may themselves be biologically active and play a role in disease propagation and/or recovery from disease in some patients with GBS.

IL-10 and IFN-gamma in Guillain-Barré syndrome. Network Members of the Swedish Epidemiological Study Group

Guillain-Barré syndrome (GBS) is an acute inflammatory disease affecting myelin and axons of the peripheral nervous system (PNS). GBS is considered to be caused by breakdown of tolerance to autoantigens of the PNS. The involvement of cytokines in GBS and in relation to treatment with high dose intravenous immunoglobulin (IvIg) is incompletely known. We studied the temporal profiles of IL-10 and IFN-gamma-secreting blood mononuclear cells (MNC) over the course of GBS, using enzyme-linked immunospot (ELISPOT) assays. Pretreatment levels of blood MNC spontaneously secreting IL-10 were higher in the acute phase of GBS than in control patients with aseptic meningitis, other neurological diseases, diabetic neuropathy and healthy subjects. Levels of IFN-gamma-secreting blood MNC were not increased over the course of GBS. Patients treated with IvIg had lower numbers of IL-10-secreting MNC compared to untreated patients. High levels of IL-10-secreting MNC correlated with serum anti-ganglioside IgM antibody levels, and with neurophysiological signs of axonal damage. The present data suggests that IFN-gamma is not involved in GBS pathogenesis, and IL-10 being up-regulated in the early phase of GBS and associated with axonal damage, may have a pathogenetic role in GBS.